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Takehiro Mikami
Takehiro Mikami
IoT Product Marketing
Published: November 19, 2021

Recently, motor applications have been required to save energy, reduce system costs, and realize the integration of electronics and mechanics.
In this article, I will introduce a motor control solution for a ceiling fan using the RX13T 32-bit MCU that realizes these requirements.
This solution realizes motor and power supply control with a single chip while reducing external peripheral components by utilizing the built-in functions of the RX13T, and simultaneously achieving added values such as system cost reduction and energy saving.

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RX13T Ceiling Fan Solution 1

This solution has three features as below:

  1. Reduces peripheral components and adopts a single-sided PCB board to reduce board cost.
    With RX13T built-in features such as a high-speed on-chip oscillator (HOCO) that ensures ±1% even when stress occurs or due to deterioration over time, programable gain amplifier (PGA), and comparator, external peripheral components can be reduced and a cheaper single-sided board can be adopted. 
  2. Realizes the implementation of a smaller inductor on-board by high-frequency PFC for power supply.
    For the integration of electronics and mechanics, a smaller inductor was mounted on-board using high-frequency PFC (carrier frequency of 50KHz) to replace a much bigger size transformer, which could not be mounted on-board before.
  3. Realizes motor control (FOC + pickup control) and PFC control with a single chip.
    Realizes motor control by FOC with pickup control that can restart during free-running, and PFC control (continuous current mode) with a single chip. This solution offers a high power factor of about 99%, which is significantly improved compared to other products without a PFC offering which is about 65%.
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RX13T Ceiling Fan Solution 2

*As a support tool for motor control development, you can use the Desk Top Lab ICS (In-Circuit Scope) or the Renesas Motor Workbench 2.0.

Renesas provides the application note, schematic of the ceiling fan inverter board (Gerber data, BOM list), and the control software free of charge. You can start to build a system immediately by referring to this solution.

Please use this solution as an example of energy saving, cost reduction, smaller footprint, and many others added values. We will continue to pursue customer value improvement in both the solutions and MCUs, so please look forward to it.

Winning Combinations: Large Power BLDC Ceiling Fan with PFC

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